According to a study conducted by ecologist Cynthia Sagers of the University of Arkansas and presented at this year's meeting of the Ecological Society for America, herbicide-resistant canola plants are dominating North Dakota.

Researchers took over 400 roadside samples – one every five miles – and found that 86 percent of the wild-growing canola plants were genetically engineered.

Although the broader consequences of this transfer from domesticated crop to weed are still being debated, farmers have had to start plowing their fields again because Roundup no longer works as a method of weed control.

Some ecologists believe that plowing has a more negative effect on the environment than herbicide use since it encourages top soil erosion.

Researchers say it will also be difficult to prevent organic canola plants from being contaminated with genetically modified canola.

Read more:

• In North Dakota, Genetically Modified Canola Goes Wild (Discover)
• GM crop escapes into the American wild (Nature)